The present invention generally relates to the field of ground soil coring equipment, and more particularly, to a soil sample core system in which a screw driven rotatable piston is used to drive a soil sample tube out of the system without disturbing the soil sample.
Many commercially available soil sampling tools usually consist of an outer cylinder and one or more serially stacked inner cylinders that fit within the outer cylinder. The tools are pushed into the ground by various means. The soil sample is collected inside the inner cylinder(s) which are usually thin wall tubes. The outer cylinder is relatively thick walled and acts as the strength member to which force is applied to push the tool through the soil. The inner tubes may also be "split" tubes, so that the tube can be "peeled" away from the soil sample.
A problem with soil sampling tools is that soil is also collected in the annulus formed between the outer and inner cylinders. If the soil is dense, abrasive, and compacted within the annulus, the inner tubes may become lodged or jammed so that they cannot easily be removed from the outer cylinder without disturbing the soil samples. When this happens, the jammed tubes need to be "hammered" out of the outer cylinder. However, such hammering generally disturbs, and in some cases destroys, the soil sample.
Therefore, a need exists for a tool for collecting soil samples which allows the soil samples to be removed without being disturbed.